Fluid metering roll and method of making the same

Abstract

A fluid metering roll such as an anilox roll is comprised of a tubular carbon fiber composition core having one or more metallic layers intervening between the core and a surface layer comprised of ceramic, the ceramic having outwardly opening fluid metering cells. The method of forming the roll includes steps of thermal spray applying one or more layers comprised of metal over the roll surface the layers intervening between the roll and an external ceramic coating. Characterizing features of the application method reside in each of the thermal spray applied layers being directed toward the core at a negative rake angle of from about 11½ to about 13½ and preferably 12½°, the core and layers which receive the thermal spray being simultaneously cooled to about 110° Centigrade or less during application of the thermal spray. The method and article are further characterized in that the coefficient of thermal expansion of the layers intervening between the core and the outermost ceramic layer form a progression whereby the intermediate layers have thermal characteristics which progressively become smaller in the outward direction.

What is claimed is:  
     
       1. The method of manufacturing a ceramic coated fluid metering roll having a carbon fiber composite core comprising the steps of providing an elongate cylindrical carbon fiber core, causing said core to rotate about its longitudinal axis, applying a thermal barrier layer comprised of metal to the surface of said rotating core via a flame spray procedure; thereafter applying a ceramic coating over said thermal barrier layer via a flame spray procedure, said spray procedures being characterized in that the spray stream is directed toward said surface at a negative rake angle displaced by from about 11½-13½ degrees from the axis of said core and by the surfaces of said core and barrier layer respectively being cooled to a temperature not greater than about 110° C. during the spray procedure. 
     
     
       2. The method in accordance with claim  1  and including the step of applying a bond layer comprised of metal over said thermal barrier layer in advance of applying said ceramic coating. 
     
     
       3. Method in accordance with claim  2  when said bond layer is applied by a flame spray technique characterized in that the spray stream is directed toward said surface at a negative rake angle displaced by from about 11½-13½ degrees from the axis of said core.